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Why do transit agencies keep falling for the hydrogen bus myth?

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Re: Why do transit agencies keep falling for the hydrogen bus myth?

#141

Post by yummypaint »

analog31 wrote: post #140
yummypaint wrote: post #126

Earlier quoted context omitted.

It absolutely was. In the event that breakthroughs happened and it became viable faster than expected, the backup plan was to get the hydrogen from fossil fuels to make sure the industry would still get its cut.

Isn't that the only plan right now? Is commercially viable hydrogen being made from any process other than the shift reaction?

Back when the Bush admin was hyping this stuff they managed to get the media to talk mostly about electrolysis of water using solar power. They would talk about how only water comes out the tailpipe, and the symmetry of being able to reuse water to make more fuel was extremely appealing to the credulous minds of the public.

Nothing has really changed either, 20 years later and laypeople still don't have better information about this technology...

Re: Why do transit agencies keep falling for the hydrogen bus myth?

#142

Post by busthrowaway23 »

bluGill wrote: post #66
abdullahkhalids wrote: post #47

Earlier quoted context omitted.

Many bus routes have a 5-10ish min break at some point (usually the main station) in the route. If you can utilize those ten minutes to do a top-up, you can go a lot further on the same sized battery.

No bus route should be more than 15 minutes between full and empty. That is you start at some station, go 15 minutes, then turn around and go back. There are many systems that attempt to do more, but there is no point: people have places to be: on the bus is not on that list. That 15 minutes means an average of 7 minutes, now they walk to some other express bus that gets them nonstop (at faster speeds) to someplace,…

Am I misunderstanding you about the 15 minutes interval?

Every workday I take a one-seat King County Metro bus ride that lasts about 1 hr. The bus starts at a layover facility and ends at a different layover facility.

I don’t see how this 15 minute interval maps to my actual commute?

Re: Why do transit agencies keep falling for the hydrogen bus myth?

#143

Post by busthrowaway23 »

bluGill wrote: post #98
bolognafairy wrote: post #93

Earlier quoted context omitted.

Sorry, but, what the hell? This is Hacker News at its finest: completely talking out of its ass. This isn’t how bus routes work, and this isn’t how people ride busses, on most if not all of the…many PT systems I’ve used in multiple states / countries.

There is a reason people complain about buses and prefer to drive in so many cases. Operators try to compromise on cheap and end up with service for those who after 5 DWIs can't get their friends to drive them anymore.

This is highly regional - any major city with a decent transit system will have excellent bus routes in dense areas. Also, “operators” usually means bus drivers, not transit agencies

Re: Why do transit agencies keep falling for the hydrogen bus myth?

#144

Post by KeplerBoy »

bombcar wrote: post #31
bobthepanda wrote: post #21

Earlier quoted context omitted.

This depends a lot on local climate and topography. Seattle has kind of been a bust with them because the hills really reduce the amount of charge, and on top of that the existing bus depots are already full, so switching to electric only would mean having to find and locate space for more bus depots, which is quite difficult.

Seattle also has (or had) trolley busses which fixed that problem. Everything is cost, it's all cost, not the ability to actually solve the problem.

I wonder if trolley busses will make a great comeback now. Seems so obvious to just put the overhead lines near a few central bus hubs, so buses can recharge during the shift.

Re: Why do transit agencies keep falling for the hydrogen bus myth?

#145

Post by londons_explore »

If hydrogen busses really were going to have a lower operational cost per mile in 2050, then some company would be offering to lease busses for $X per mile to transit operators, fuel included, for a 25 year lease. They'd make a loss initially, but big profits later.

That approach turns this technology maturation and cost risk into a market, and those with most expertise can then put their own money on the line to help everyone make the right decision.

Re: Why do transit agencies keep falling for the hydrogen bus myth?

#146

Post by AnthonyMouse »

MostlyStable wrote: post #132
AnthonyMouse wrote: post #96

Earlier quoted context omitted.

That is called a series hybrid and the reason they're not popular is that the power split device in common hybrids is simply better. The power split device isn't an ordinary transmission, it's a set of planetary gears with a fixed gear ratio between three shafts. One goes to the wheels, the other two to the engine and the electric motor respectively. The ratio of the engine speed to the wheel speed is then set by the…

Wouldn't an additional advantage of series hybrids be that the engine can be tuned to operate solely in it's most efficient RPM band, since it just charging the battery and doesn't need to deal with changing speeds? This can (according to some very cursory googling), result in efficiency gains of 20-30% relative to the least efficient RPMs. This should at least partially offset some of the size and weight considerati…

The parallel hybrids can already do that because of the CVT.

In practice they also allow the engine to run at higher speeds under heavy acceleration because the peak efficiency RPM and the peak power RPM are different and the assumption is that if the driver is stomping on the accelerator they want to resolve the power/efficiency trade off in favor of power right now, which is another thing the series hybrids can't do.

Re: Why do transit agencies keep falling for the hydrogen bus myth?

#147

Post by rsynnott »

jrussino wrote: post #131
rsynnott wrote: post #6

Huh. I kind of thought that batteries had comprehensively won in this market, tbh. I still can't quite get used to the electric buses. A 20 tonne double-decker bus should sound like it might explode at any moment; it is unnatural for them to move around more or less silently.

> A 20 tonne double-decker bus should sound like it might explode at any moment I hope you're using "should" as in "that's what I'm accustomed to" rather than "that's how it ought to be"... right? :-D Personally I feel like quieting buses would be a huge step toward making day-to-day city life more pleasant.

Yup, wasn’t being entirely serious. They’ve gotten progressively quieter over the last few decades; when I was a kid, they really did sound like they were within seconds of complete failure when going up a hill. The electric ones are a shock the first time you get on one, though - very futuristic.

Re: Why do transit agencies keep falling for the hydrogen bus myth?

#148

Post by KeplerBoy »

jrussino wrote: post #131
rsynnott wrote: post #6

Huh. I kind of thought that batteries had comprehensively won in this market, tbh. I still can't quite get used to the electric buses. A 20 tonne double-decker bus should sound like it might explode at any moment; it is unnatural for them to move around more or less silently.

> A 20 tonne double-decker bus should sound like it might explode at any moment I hope you're using "should" as in "that's what I'm accustomed to" rather than "that's how it ought to be"... right? :-D Personally I feel like quieting buses would be a huge step toward making day-to-day city life more pleasant.

Busses are not going to be quiet. Around here we have pretty cool "Van Hool ExquiCity" trolley busses and they can glide gracefully at slow speeds, but when they are hurtling down patched up streets they are not much quieter than the traditional busses.

Re: Why do transit agencies keep falling for the hydrogen bus myth?

#149

Post by AtlasBarfed »

fraserharris wrote: post #119

AC Transit (eg: East San Francisco Bay) performed a detailed 2 year study (July 2020 - June 2022) comparing newer Hydrogen Fuel Cell & Battery -powered buses to existing Diesel, Fuel Cell, & Hybrid -powered buses, 5 of each type. The key results are the Hydrogen Fuel Cells have significantly more expensive infrastructure, fuel, and maintenance costs than Battery. However, both technologies are still less reliable tha…

I'm not going to dispute your numbers with diesel versus EV reliability, but I have to think the simplicity of an EV drivetrain will win that battle in the next version or two.

Re: Why do transit agencies keep falling for the hydrogen bus myth?

#150

Post by AnthonyMouse »

mike-the-mikado wrote: post #139
adrian_b wrote: post #110

Earlier quoted context omitted.

It is impossible for a hilly terrain to reduce the range by a third for well-designed electric buses. The efficiency of regenerative braking increases with the power of the vehicle. The electric efficiency should be well over 90%, perhaps even 95%. The mechanical losses will lower the total efficiency to much smaller values, but even so, the total efficiency should be over 80%. A bus with an ICE will consume 5 times…

If the passengers all ride up hill and walk down hill?

Or they ride up hill and then get off the bus for the night because the residential district is at a higher elevation than the business district.
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